1. Field of the Invention
This invention relates to a conduit or pipe-like structure having means to disperse liquid from the interior of the conduit to the exterior thereof by means of a spongelike dispersion element which is liquid permeable and generally structured to transfer liquid therethrough by capillary action.
Description of the Prior Art
The importance and concept of irrigation has been well known and practiced for many years. In the past, various systems including open canals, ditches, etc. have been used to convey water from an adequate source to various land masses for the obvious purpose of moistening soil and thereby encourage cultivation. While such "primitive" methods are still in common use today, the disadvantages of these prior art systems are well known.
In order to supplement such systems in a more efficient manner, water is frequently conveyed by systems of pipes or conduits in which sprinkling devices are installed at spaced points along the length of the conduit. Water, either by itself or carrying a soil enriching substance is pumped through the pipe and discharged to the land at the desired or predetermined point. Frequently, sprinklers attached to the water carrying irrigation conduit further disperse the water, under pressure, to areas other than the half defined by the conduit itself. However, sprinkling in this manner sometimes includes the inherent disadvantage of substantial loss of water through evaporation and run-off.
The irrigation and farming industry has discovered that when placing irrigation conduits on the surface or immediately below the surface of the ground, a frequent problem of clogging has been encountered. In this sense it is common for the soil to enter the apertures in the conduit or irrigation pipe through which water is intended to exit. If the irrigation pipe remains inoperative for any relatively long period of time, the soil becomes firmly implanted within the spray apertures of the conduit resulting in certain portions of the irrigation pipe becoming inoperative. To overcome this problem, the prior art includes the use of a porous receptacle or conduit placed in the ground so that the soil surrounding the receptacle or conduit may be moistened by seepage of the liquid through the porous walls of the pipe. While eliminating a number of problems concerned with the clogging aspect set forth above, the system further includes the advantage of reducing evaporation and run-off. However, such a system is not well adapted for the distribution of liquids over substantial areas. Such a porous conduit or receptacle structure is disclosed in the U.S. Pat. to Weitzel, No. 2,807,505.
Other U.S. patents generally representing the state of the art of irrigation devices include the following U.S. Pat. Nos. 3,870,236, Sahagun-Barragan; 3,797,754, Spencer; 2,798,768, Babbin; and 2,769,668, Richards. While the structures represented in the above-noted U.S. Patents are operable and functional, and certainly adaptable for certain irrigation purposes, a number of these representative devices do incorporate inherent problems set forth above.